Vertical blade louver



Oct. 24, 1967 R. w. LANE ETAL 3,348,466

VERTICAL BLADE LOUVER Filed Oct. 16, 1964 2 Sheets-Sheet 1 INVENTORSOBERT W. LANE EARL. F. MHTHERS A 7- TOR/YE YJ Oct. 24, 1967 R. w. LANEETAL VERTICAL BLADE LOUVER 2 Sheets-Sheet 2 Filed Oct. 16, 1964INVENTORS ROBERT W. LANE.

EARL F. MRTHERS A TTORNE m- United States Patent 3,348,466 VERTICALBLADE LOUVER Robert W. Lane and Earl F. Mathers, Marietta, Ohio,assignors to The Airolite Company, Marietta, Ohio, a corporation of OhioFiled Oct. 16, 1264, Ser. No. 404,347 2 Claims. (Cl. 98--121) Thisinvention relates in general to ventilating louvers for air-conditioningsystems and, more particularly, to louvers of this type wherein the airintake side is exposed to the weather.

The air in an occupied space should at all times be free from toxic,unhealthful or disagreeable fumes, and also should be relatively freefrom odors and dust. To obtain these conditions, enough clean outsideair must always be supplied to an occupied space to counteract oradequately dilute the sources of contamination. Accordingly, in thedesign of air-conditioning systems for buildings or residences airinfiltration is an important factor, and each system is commonlyevaluated in terms of the number of air changes per hour it provides. Inmost air-conditioning systems a large amount of air is re-circulatedover and above the amount required to satisfy minimum ventilationconditions. Because of this increased demand for air in quality andquantity, the design of efiicient ventilating louvers is ofever-increasing importance. However, attempts to achieve an optimumlouver design have frequently met with failure because of the severalproblems and design limitations which arise, especially when one side ofthe louver is exposed to normal weather conditions. Louvers of this typemust not only satisfy airflow requirements, but must additionallyprevent rain and mist from passing through to the interior of thebuilding or residence. To achieve this, however, the various barriersemployed by the louvers now commercially available have not beensatisfactory, largely because of their detrimental effect upon theairflow. In addition, these same prior art devices have not been totallyeffective when extreme weather conditions are encountered. Otherconsiderations as to cost, overall appearance, ease of installation,durability and their ability to minimize air frictional resistance orpressure drop, go far in determining the utility of such devices. It istherefore the principal object of this invention to provide aventilating louver which will eliminate the foregoing shortcomings inthe prior art devices and which is capable of optimum performance over awide range of atmospheric conditions.

Louvers made according to this invention accomplish these resultsthrough the use of vertical blades which define Z-shaped airpassageways. These blades have extensions into the air passageways indirection to cause maximum turbulence thus to facilitate removal ofmoisture from the air passing therethrough. Inlet and outlet weatherstops consisting of vertically extending integral portions of the bladesalso serve to induce turbulence. The constrictions to the airpassageways caused by the weather stops and the extensions cause airvelocity and pressure differences which further facilitate removal ofwater from the airstream, and all of the blades and their associatedextensions and stops serve to carry the water deposited thereon directlyto the sill without permitting it to again become air-borne. Ahorizontal exterior weather shield extends across the forward portion ofall the blades in closely spaced relationship to the bottom front sillplate to provide a wind shield to prevent the moisture drawing down theblades from again being picked up and carried in the airstream throughthe louver, and to provide between the sill and the shield a weep slotthrough which the collected moisture can drain to the outside of thelouver.

3,348,466 Patented Oct. 24, 1967 In the drawings,

FIG. 1 is a perspective view showing the overall design of the louver,with parts removed to simplify the disclosure;

FIG. 2 is a view taken along the line 2-2 of FIG. 3;

FIG. 3 is a view taken along the line 33 of FIG. 1; and

FIG. 4 is an enlarged view showing in cross-section the specificconstruction of the blades.

Referring to the drawings, and particularly to FIGS. 1 and 2, theinvention is shown comprising a plurality of metal blades 6 which arearranged in parallel spaced relation and are fixedly secured between anupper channel 'member 8 and a similar lower channel member 10: Thechannel members 8 and 10 are provided with inner U-shaped splicingelements 12 and 14 which reinforce the composite structure andfacilitate the innerconnection of additional louvers. At 16, 16 is shownthe vertical end casings having outer surfaces 17, 17 adapted to engagethe confronting surface of the wall opening. Accordingly, the horizontalchannel members 8 and 10 in conjunction with the vertical end casingsform a structurally rigid enclosure or framework for the blades 6. Thelower channel member 10 includes an exterior surface 18 which extendshorizontally so as to constitute a lower sill plate for the louver.Shown in parallel spaced relation with the sill 18 is the back sillplate 19'.

The specific structure of each of the blades 6 is best shown in FIGS. 3and 4 and includes an inlet section 20, an outlet section 21 and aninner section 22. The inlet section 20 is shown disposed at an acuteangle 23 relative to the frontal plane of the louver and is connected tothe section 22 at a point intermediate of the length thereof so as toform the front protruding extensions 26. Similarly, the outlet sections21 are disposed at an'acute angle 28 relative to the back plane of thelouver and are connected to the section 22 so as to form the backextensions 30. The numbers 32 and 34 refer to the respective anglesformed at the intersection of the sections 20 and 21 with the innersection 22. While in this particular embodiment the angles 23 and 28 areat 45 degrees and the angles 32 and 34 are at degrees, it is to beunderstood that satisfactory results have been achieved by varying theseangles slightly.

There is thus provided a plurality of parallel spaced blades each ofwhich are substantially Z-shaped in crosssection and which cooperate inpairs to form a series of small passages for conveying the air throughthe louver. As shown in the enlarged view of FIG. 4, each of thesepassages are further subdivided into air inlet passages 36, air transferpassages 38 and the air outlet passages 40. The forward extensions 26are disposed in coplanar relation with the inner sections 22 and projectinwardly into the inlet passages 36. Back extensions 30 are disposed in:coplanar relation with the outlet sections 21 and project inwardly intothe transfer passages 38.

Formed integrally with the inlet sections 20 are vertical weather stops42 whch preferably consist of flat metal strips of rectangularcross-section so as to provide outer and inner surfaces 44 and 46,respectively, and the leading edges 48 and 50.

Similarly, rear stops 52 are formed integrally with outlet-sections 21and preferably consist of fiat metal strips of rectangular cross-sectionso as to provide interior and exterior surfaces 54 and 56, respectively,and the trailing edges 58 and 60.

At 62 is shown a front exterior shield which extends completely acrossthe front of the louver and in spaced horizontal alignment with thefront sill plate 18 so as to form weep slot 64. The shield 62 is securedby rivets 66. Similarly, a rear shield 68 extends completely across it)the back of the louver and in spaced parallel relation with the frontshield 62.

As will be readily appreciated by those familiar with the many problemsand factors involved in the design of air ducts and air distributionsystems, the dimensions of the various components and their geometricalrelationships are critical in determining their effect .upon theairflow. Accordingly, the invention will be: illustrated by thefollowing example listing the specific dimensions and trigonometricvalues of one such louver blade which performed admirably over a widerange of air velocities and adverse atmospheric conditions.

TABLE A Blade thickness inches .08 Louver height do 72.00 Distancebetween blades do 2.00 Length of section 20 do 1.60 Length of section 21do.. 1.68 Length of section 22 do 1.80 Angle 23 degrees 45 Angle 28 do45 Angle 32 do 90 Angle 34 do 90 Front extensions 26 inches .56 Backextensions 30 do .38 Front stops 42 (.08 inch thick) do .75 Rear stops52 (.08 inch thick) do .75 Weep slot height do .50

It is to be understood that the foregoing is submitted by way of exampleonly and that effective results have been achieved by varying certain ofthe dimensions listed above. For example, the width of the frontextensions 26, as listed in Table A represents 21% of the distancebetween the blades. However, by extensive testing in wind tunnelconditions, the effective range has been determined to be 18% to 23% ofthe distance between the blades. Additional relationships which havebeen deter mined are illustrated by the following table.

TABLE B Ratio: Effective range, percent Back extensions Slit/distancebetween blades 12 to Front stops 42/ distance between blades 30 to 38Back stops SZ/distance between blades 30 to 38 The operation of theinvention is best understood by tracing the airflow through theindividual passages. Assuming normal conditions, air entering the louverin the direction of the arrow of FIG. 4 would contain water droplets ormist which, of course, must be prevented from passing to the interior orbackside of the louver. To achieve this end, the component parts of thelouver are each designed to help in removing a portion of the water andthe combined effect is the total elimination of water from the airstream leaving the louver. The effect of each component part upon thepassing air stream will now be considered.

The front exterior shield 62 is adapted to provide increased weatherprotection when adverse conditions are encountered, such as rainaccompanied with heavy blowing. By means of the weep slot 64, properdrainage of any water accumulation on the sill is provided. The rearshield 68 is used as a dam to keep water from running into the interioror backside of the louver. As will be appreciated, the height of theweep slot 64 becomes critical since too great a slot height would permitthe water on the sill to be blown over the rear sill plate while toosmall a height would not provide proper drainage of the water. Theoptimum height has been determined to be approximately /2 inch.

The front protruding extensions 26 are designed to check the passage ofwater and mist by inducing turbulence inside the louver and therebycause the water particles to be deposited on the inlet sections and onthe extensions 26 themselves, and also serving as vertical channels tocarry the extracted water to the sill. Their distance of protrusion intothe air stream is determined to produce maximum turbulence andprotection without greatly reducing the airflow in c.f.rn. Backextensions 30 similarly effect the air down stream as it enters theoutlet passages 40.

The advantages of the Z-shaped design is manifested by the fact that theair is restricted in the vicinity of the transfer passages 38 andallowed to expand in the vicinity of the outlet passages 40. Since thevelocity of the passing air varies inversely with the cross-sectionalarea of the passages, it is apparent that the velocity of the airincreases near the reduced areas near the center of the louver andreduces by expansion in the increased areas of the outlet passages. Thisvelocity change coupled by the fact that the air is simultaneouslysubjected to a direction change, has been found extremely effective forextracting water from the air stream.

The front stops 42 are designed to serve a dual purpose. First, becauseof their perpendicular abutment with the passing air-stream, a portionof the water is restricted from entering the louver and is deposited onthe stops upon contact therewith. These stops also serve to carry anywater deposited thereon to the sill below. Secondly, the stops 42restrict the air entering the louver and thus cause an immediatevelocity change which also combines to induce turbulence in the airstream. Rear stops 52, being disposed in a direction opposed to thedirection of the front stops 42, are adapted to facilitate expansion ofthe air exhausting from outlet passages 40.

There is thus provided a ventilating louver capable of optimumperformance over a wide range of atmospheric conditions and which iscapable of fulfilling the foregoing listed objectives, as well asothers.

What is claimed is:

1. In an air ventilating louver having upper and lower blade supportingmembers and a front sill plate,

(A) a plurality of vertically extending blades mounted between saidsupporting members in spaced parallel relation, said blades being insubstantially Z- shaped cross-section and oriented so as to define:

(1) a series of air inlet passages each of which are disposed at anacute angle with reference to the plane of said sill plate,

(2) a corresponding series of air outlet passages each of which isdisposed at an acute angle with reference to the plane of said sillplate and which are in substantially parallel spaced relation withrespect to said inlet passages,

(3) a series of air transfer passages in interconnecting communicationwith corresponding pairs of said inlet and outlet passages, saidtransfer passages disposed in a direction substantially perpendicular tothe direction of said inlet and outlet passages and being adapted toinduce turbulence in the air passing through said louver;

(B) a plurality of vertically extending inlet stops mounted on each ofsaid blades being adapted to restrict the air entering said inletpassages and. to facilitate the removal of water therefrom, said inletstops comprising fiat metal strips, the width of which are dimensionedso as to be in the range of 30% to 38% of the distance between theblades;

(C) a plurality of vertically extending outlet stops mounted on each ofsaid blades being adapted to expand the air leaving said outlet passagesand to facilitate removal of air therefrom, the width of said outletstops being dimensioned so as to be in the range of 30% to 38% of thedistance between the blades; and

(D) an exterior weather shield consisting of a rigid flat plateextending in closely spaced horizontal alignment approximately one-halfinch above said front sill plate.

2. A ventilating louver comprising,

(A) upper and lower horizontal blade supporting members,

(B) front and back sill plates,

(C) a plurality of vertically extending blades mounted between saidsupporting members in spaced parallel alignment with respect to eachother, each of said blades including (1) air inlet and outlet sectionsdisposed in parallel spaced relation and at an acute angle withreference to the plane of said front sill plate,

(2) an inner air transfer section uniting said inlet and outlet sectionsand disposed substantially perpendicular to the planes of said inlet andoutlet sections,

(3) a first protruding section at the intersection of said inlet andinner sections and extending in coplanar relation with respect to saidinner section and substantially perpendicular to the plane of said inletsection, said first protruding section being adapted to induceturbulence in the air a passing in the vicinity of said first protrudingsection, (4) a second protruding section at the intersec- (D) anexterior weather shield consisting of a rigid fiat plate extending inclosely spaced horizontal alignment approximately one-half inch abovesaid front sill plate and in coplanar relation therewith.

References Cited UNITED STATES PATENTS l/1906 Carrier 55-257 9/1934Hinkle 98-121 2/1960 Lindgren 98-121 X 10/1961 Starbuck et a1 55-257 X4/1963 Doolittle 98-121 tion of said outlet and inner sections andextending in coplanar relation with said outlet section andsubstantially perpendicular to the ROBERT A. OLEARY, Primary Examiner.

M. A. ANTONAKAS, Assistant Examiner.

1. IN AN AIR VENTILATING LOUVER HAVING UPPER AND LOWER BLADE SUPPORTINGMEMBERS AND A FRONT SILL PLATE, (A) A PLURALITY OF VERTICALLY EXTENDINGBLADES MOUNTED BETWEEN SAID SUPPORTING MEMBERS IN SPACED PARALLELRELATION, SAID BLADES BEING IN SUBSTANTIALLY ZSHAPED CROSS-SECTION ANDORIENTED SO AS TO DEFINE: (1) A SERIES OF AIR INLET PASSAGES EACH OFWHICH ARE DISPOSED AT AN ACUTE ANGLE WITH REFERENCE TO THE PLANE OF SAIDSILL PLATE, (2) A CORRESPONDING SERIES OF AIR OUTLET PASSAGES EACH OFWHICH IS DISPOSED AT AN ACUTE ANGLE WITH REFERENCE TO THE PLANE OF SAIDSILL PLATE AND WHICH ARE IN SUBSTANTIALLY PARALLEL SPACED RELATION WITHRESPECT TO SAID INLET PASSAGES, (3) A SERIES OF AIR TRANSFER PASSAGES ININTERCONNECTING COMMUNICATION WITH CORRESPONDING PAIRS OF SAID INLET ANDOUTLET PASSAGES, SAID TRANSFER PASSAGES DISPOSED IN A DIRECTIONSUBSTANTIALLY PERPENDICULAR TO THE DIRETION OF SAID INLET AND OUTLETPASSAGES AND BEING ADAPTED TO INDUCE TURBULENCE IN THE AIR PASSINGTHROUGH SAID LOUVER; (B) A PLURALITY OF VERTICALLY EXTENDING INLET STOPSMOUNTED ON EACH OF SAID BLADES BEING ADAPTED TO RESTRICT THE AIRENTERING SAID INLET PASSAGES AND TO FACILITATE THE REMOVAL OF WATERTHEREFROM, SAID INLET